CPU Fan having problems! Need Help!

Ok, here's the deal. I am working on a computer for my girlfriend. Its about a year old HP computer.

It starts up, power seems to be fine, then the front two lights blink. One being yellow for power, the other being green for when its working. They both constantly blink and the cpu fan starts to make a kind of "chugging" noise. Like it's cutting out...but it still doesnt seem like it is having problems.

So..I go out to best buy thinking that it is a problem with my power supply...the power supply in it was some bestec power supply before. I went and bought a Dynex power supply...it was cheap...but non-the-less a new power supply(and I never had problems with any other Dynex products). So I set it all up....put the IDE cables in the right spots, connect power to the chassis fan, and it boots up when I plug it in. I can eject the cd drive, it seems like its working. About 4 seconds later, the cpu fan is making the same noise, a slight chugging sound, kind of like it is dying out....but its not making any squealing or anything else....so I don't know what the problem is...any help would be appreciated..

Does your machine do anything ?? As in, does it POST ?? Does it boot ?? Can you get into the BIOS ?

With the way you are describing the problem, my initial thought is that your motherboard is faulty, however, with more detail we'll be able to pinpoint the problem.

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1.) It is O.K. to call hooters 'knockers' and sometimes snack trays
2.) It is wrong to be French
3.) It is O.K. to put all bad people in a giant meat grinder
4.) Lawyers, see rule 3
5.) It is O.K. to drive a gas guzzler if it helps you get babes
6.) Everyone should car pool but me
7.) Bring back the word 'stewardesses'
8.) Synchronized swimming is not a sport
9.) Mud wrestling is a sport

Yea, Im gonna figure that it is also the cause of a faulty mother board. It doesn't do anything else, the fans, all of the fans now that I have listened to every single one of them, make the "chugging" noise. I went ahead and plugged another motherboard in, and tried the fans then. They worked fine, and everything. So, it is the cause of a faulty motherboard. So I went ahead and ordered a ASUS Micro-Atx motherboard for this pc. Thanks for your help though, even though I found the problem already.

1.) It is O.K. to call hooters 'knockers' and sometimes snack trays
2.) It is wrong to be French
3.) It is O.K. to put all bad people in a giant meat grinder
4.) Lawyers, see rule 3
5.) It is O.K. to drive a gas guzzler if it helps you get babes
6.) Everyone should car pool but me
7.) Bring back the word 'stewardesses'
8.) Synchronized swimming is not a sport
9.) Mud wrestling is a sport